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MODIS Calibration Workshop

MODIS Calibration Workshop. Jack Xiong Sciences and Exploration Directorate, NASA/GSFC and MODIS Characterization Support Team (MCST). MODIS Calibration Workshop, Linthicum, MD (May 13, 2008). Agenda. Instrument and Performance Status Updates

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MODIS Calibration Workshop

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  1. MODIS Calibration Workshop Jack XiongSciences and Exploration Directorate, NASA/GSFCand MODIS Characterization Support Team (MCST) MODIS Calibration Workshop, Linthicum, MD (May 13, 2008)

  2. Agenda • Instrument and Performance Status Updates • 9:00-9:10 Introduction and Instrument Status: Jack Xiong • 9:10-9:25 IOT Status: Roy Yi • 9:25-9:40 L1B Status: James Kuyper • 9:40-9:55 TEB Status: Aisheng Wu • 9:55-10:10 RSB Status: Hongda Chen • 10:10-10:30 Spatial/Spectral Status: Jason Choi & Jack Xiong • 10:30-10:45 Coffee Break • Collection 6 Issues • 10:45-11:15 Intro + Proposed QA & TEB Changes: Brian Wenny • 11:15-11:45 Proposed RSB Changes: Junqiang Sun • Open Discussion • 12:00-1:30 Lunch • Science Discipline Presentations • 1:30-2:00 Geometric Calibration Status: Robert Wolfe • 2:00-2:20 Chris Moeller • 2:20-2:40 Eric Vermote • 2:40-3:10 Ewa Kwiatkowska • 3:10-3:25 Coffee Break • 3:25-3:55 Special Issues: Jack Xiong • Open Discussion • 4:45-5:00 Summary & Action Items: Jack Xiong & All

  3. MCST Contacts • Instrument operation: Roy Yi • L1B and LUT: James Kuyper • RSB Calibration: Junqiang Sun / Hongda Chen • TEB Calibration: Aisheng Wu / Brian Wenny • Spectral and Spatial: Jason Choi • General Information: Brian Wenny and Jack Xiong http://www.mcst.ssai.biz/mcstweb/index.html • Information on MODIS Operation, Calibration, L1B Code & LUTs • L1B ATBD and MCST Publications • Workshop Presentations (current and previous)

  4. Acknowledgements • MCST Groups: IOT, L1B/LUT, and Calibration • MODIS Science Team • Science Team Leader (Vince Salomonson) • Land (Eric Vermote and Zhengming Wan) • Ocean (Gerhard Meister et al.) • Atmosphere (Chris Moeller) • Cal/Val (Stu Biggar et. al) • Raytheon / SBRS MODIS Team • Recently transitioned to Raytheon El Segundo • Others • Bill Barnes, Bruce Guenther, Eugene Waluschka, and Robert Wolfe

  5. Instrument Status • Instrument Background (for reference purposes) • On-orbit Calibration Activities • Key Telemetry Trending • Instrument temperature • FPA temperature • Blackbody • Summary of Instrument Status (operation/calibration)

  6. Instrument Background • 2-sided Paddle Wheel Scan Mirror • 3 Nadir Spatial Resolutions • 250m (1-2), 500m (3-7), and 1km (8-36) • 4 Focal Plane Assemblies (FPAs) • VIS, NIR, SMIR, and LWIR • 36 Spectral Bands (490 detectors) • Reflective solar bands (1-19, and 26), thermal emissive bands (20-25, 27-36) • On-Board Calibrators (OBCs): • Solar diffuser (SD) • SD stability monitor (SDSM) • Blackbody (BB) • Spectro-radiometric calibration assembly (SRCA) • Space view (SV) • Science Applications • Land, oceans, and atmosphere • Nearly 40 science products generated and distributed PFM FM1 Terra (EOS-AM): Launched on 12/18/99 First light on 02/24/00 Aqua (EOS-PM): Launched on 05/04/02 First light 06/24/02

  7. MODIS Focal Plane Assemblies (FPA) S: scan direction; T: track direction B13 and B14 have 2 columns of detectors for TDI high and low gain output

  8. MODIS Key Specifications

  9. MODIS Calibration Activities SDSM BB (quarterly) SD/SDSM (weekly first year to bi-weekly) SRCA (monthly radiometric, bi-monthly spatial, quarterly spectral) Maneuvers (roll: monthly Moon; yaw: 2 for Terra and 1 for Aqua; pitch: 2 for Terra) Solar Diffuser SRCA SDSM Blackbody Scan Mirror Space View Moon SRCA is currently operated at reduced frequencies (30W configuration removed). This has no impact on radiometric calibration. Starting from July 2, 2003, Terra SD door fixed at open with SD screen down; more efforts for SD calibration data analysis

  10. Terra Instrument and FPA Temperatures ~3K increase over 8 years ~3K increase over 8 years

  11. Aqua Instrument and FPA Temperatures ~1.5K increase over 6 years ~1.5K increase over 6 years

  12. MODIS BB Temperatures

  13. Summary of Instrument Status • Both instruments continue to operate normally • All on-board calibrators continue to perform designed functions • Terra SD door fixed at open (July 2, 2003) with SDSM operated normally; Aqua SD/SDSM continued to operate on a regular basis • SRCA 30W configuration removed (2005 for Aqua MODIS, 2006 for Terra MODIS); No impact on radiometric calibration • BB temperatures (290K for Terra, 285K for Aqua) remained to be stable • Instrument and FPA temperatures remain stable • Instrument and warm FPA temperature drift: less than 3K for Terra MODIS (over 8 years); less than 2K for Aqua MODIS (over 6 years) • Cold FPA temperature controlled at 83K (A-side for Terra MODIS via LWIR; B-side for Aqua MODIS via SMIR) • Aqua cooler margin is a concern for CFPA short-term stability (unable to completely control the CFPA to the setting temperature)

  14. MODIS Instrument Operations(Details provided in backup slides)

  15. Recent Events (Terra/MODIS) • Spacecraft Events • June 7, 2007 SSR DMU swap which allowed for more data storage for MODIS (data loss occurred during swap operation) • Number of Supersets increased from 32 to 33 • No change in SSR configuration (current SSR configuration considered “limit” of no loss operations with current TDRSS scheduling) • Three instances of SFE anomalies: one in Nov., one in Dec. 2007, and April 2008 (data loss occurred). • MODIS Events • No new events since 01/31/2008

  16. Recent Events (Aqua/MODIS) • Spacecraft Events • December 2, 2007 SSR anomaly (small data loss). • SSR is currently not in a nominal configuration, but all data collection has resumed with no impact on data processing • Currently a software fix is in place to correct for the hardware error. A meeting will be held to discuss possible hardware fixes. • MODIS Events • No new events since 01/31/2008 • Several calibration events were cancelled/ postponed to support S/C SSR anomaly analysis/resolution

  17. Terra/MODIS OBC Operations • Total Number of Terra OBC Operations Since Launch • SD/SDSM: 562 • Blackbody: 63 • SRCA: 265 • (Includes Spectral, Radiometric, and Spatial) • Electronic Calibration: 55 • Lunar Calibration: 78

  18. Aqua/MODIS OBC Operations • Total Number of Aqua OBC Operations Since Launch • SD/SDSM: 364 • Blackbody: 23 • SRCA: 139 • (Includes Spectral, Radiometric, and Spatial) • Electronic Calibration: 35 • Lunar Calibration: 53

  19. Future Operational Considerations • Aqua MODIS SD door movements • Aqua MODIS CFPA temperatures Detailed IOT information (weekly reports, history, anomaly reports, etc.) are available through the MCST website: http://www.mcst.ssai.biz/IOT/index.shtml

  20. MODIS Level 1B and LUT Status (Details provided in backup slides)

  21. Recent Code and L1B Updates • L1B code has been relatively stable • 7 minor code changes made since end of 2004 (4 for Terra MODIS and 3 for Aqua MODIS) • Near-monthly LUT update for each MODIS forward processing • 6 for Terra MODIS and 2 for Aqua MODIS in 2008 to date • Additional LUTs generated, tested, and delivered to OBPG (Ocean Biology Processing Group ) for special investigations • Special LUTs produced to support FEWSN (Famine Early Warning Systems Network) • Most LUT updates were driven by response changes of VIS bands

  22. Number of MCST L1B Code and LUT Versions (as of 5/12/2008) Since 2004, L1B code has been relatively stable:

  23. 5.0.38(2007260) 5.0.40 (2008024) 5.0.6(2005066) Production Start 2.4.2(2000171) 3.0.0(2001144) 2.3.2(2000077) 2.4.4(2000287) 3.0.1(2002056) 4.2.0 (2003234) 4.3.0 (2003356) 2.4.3(2000231) 2.5.4(2000328) 2.5.5(2001044) 4.1.2 (2003030) Code Versions 1-34 1- 4 1- 4 LUT Versions 2-7 0,1 3-9 1-9, 11-58 1-11 3 0 0-2 1 1,2 0 Collection 2: Aqua Forward Processing Collection 3: Collection 4: 5.0.35(2008023) Production Start Collection 5: 5.0.7(2005185) 4.2.1 (2003233) 4.3.1(2004018) 3.1.0(2002158) 4.1.3(2003022) 4.1.1(2002304) Code Versions 1- 2 2-27 LUT Versions 0-3 0,1 0-11 4-8 1-36 Year 2009 2000 2001 2002 2003 2004 2005 2006 2007 2008 MODIS MOD_PR02 L1B Code/LUTs Major Production Changes Timeline Terra Forward Processing

  24. Most Recent Production Changes to MOD_PR02 TERRA L1B Code

  25. Most Recent Production Changes to MOD_PR02 AQUA L1B Code

  26. Collection 6 Code Changes for L1B • Change to no longer interpolate the values of dead detectors from nearby good detectors. • Waiting since 2008-03-13 for MCST, Discipline approval of one-day Golden Tiles test results. This will be followed by a 16-day Golden Tiles test. • Noisy detector (sub-sample) flagging • Results from first test run produced 2008-03-28. Will be released for MCST and Discipline approval as soon as internal review is complete. • Special Handling for the case where SV DN==0. • Initial data collection completed 2008-04-28. Need to analyze data before deciding what special handling, if any, is needed for SV DN==0. Currently considering three options: • No special handling: current code • Mark as bad only if exactly 0 • Mark as bad if the DN is below some threshold which will depend upon the band and the detector; it might also have time dependence

  27. MODIS TEB Calibration Status

  28. TEB Calibration Performance • TEB Calibration Algorithm • Terra and Aqua TEB On-orbit Performance • BB Stability • b1 & NEdT Trending • Noisy Detector History

  29. Calibration coefficient, b1, from BB RVS: Response Versus Scan-angle e: Emissivity L: Spectral band averaged radiance dn: Digital count with background correction Source radiance with RSR integration: EV: Earth View SV: Space View BB: Blackbody SM: Scan Mirror Cav: Instrument Cavity Calibration is performed for each band, detector, mirror side Calibration is performed on a scan-by-scan basis OBC BB is normally set at 290K/285K for Terra/Aqua MODIS a0 & a2 derived from pre-launch or periodic warm-up/cool-down cycles (270-315 K) of the BB TEB Calibration Algorithm Radiance (TOA), LEV

  30. TEB On-orbit Performance Thermal Emissive Bands (16 bands and 160 detectors) • Terra MODIS • Stable short-term and long-term response trends (excluding sensor configuration changes and instrument reset events) • 25 noisy detectors and 1 inoperable detector (B29 D6) • Aqua MODIS • Stable short-term and long-term response trends • 3 noisy detectors (1 new since last STM B29 D2) and 1 inoperable detector (B36 D5)

  31. Terra BB Short-term Stability δT ~ 25mk 1-granule, scan-by-scan, 12 individual BB thermistors

  32. Terra BB On-Orbit Performance

  33. Aqua BB Short-term Stability δT ~ 15mk 1-granule, scan-by-scan, 12 individual BB thermistors

  34. Aqua BB On-Orbit Performance

  35. Terra TEB MWIR Response Trend Normalized b1 (MS1)

  36. Terra TEB LWIR Response Trend Normalized b1 (MS1)

  37. Aqua TEB MWIR Response Trend Normalized b1 (MS1)

  38. Aqua TEB LWIR Response Trend Normalized b1 (MS1)

  39. Terra MODIS Noisy Detector HistoryDetectors in Product Order

  40. Aqua MODIS Noisy Detector HistoryDetectors in Product Order

  41. MODIS RSB Calibration Status

  42. Outline • RSB calibration algorithm • Noisy & inoperable RSB detector update • RSB response trending • RSB mirror side ratio trending • Solar Diffuser degradation • Summary of RSB overall performance

  43. RSB Calibration Algorithm • Solar Diffuser (SD) Calibration • SD Stability Monitor (SDSM) • 9 detectors with wavelengths from 410 ~ 940 nm • Data acquired form two paths: sun view and SD view for • Lunar Calibration • Moon observations via the SV port at a near-constant phase angle • 9~10 lunar observations each year • Lunar coefficients used for RVS calculations (view geometry will be corrected, as well as an over-sampling factor for multiple scans) • Earth View Mirror Side Ratio

  44. Summary of RSB Overall Performance • Terra MODIS (8.5 years) • No QA updates for RSB detectors since last workshop (01/2008) • Bi-weekly SDSM operation to track SD degradation • SD observations made every orbit, as SD door has remained open since July 2003 (with increased SD degradation). • Large response changes in VIS bands; noticeable mirror side differences (as high as 15% in band 8). • Aqua MODIS (6 years) • No QA updates for RSB detectors since last workshop (01/2008) • SDSM operation and SD calibration are performed on tri-weekly basis to preserve remaining number of SD door movements. • Large response changes in VIS bands. Small mirror side differences (<1.5% in band 8).

  45. Terra Aqua Detectors in Production order MODIS RSB Noisy & Inoperable Detectors • No QA updates for RSB detectors since last workshop (01/2008)

  46. Terra RSB Response Trending

  47. Aqua RSB Response Trending

  48. Terra RSB Response Trending (Moon/SD) SD and Lunar responses (trending) are used to track MODIS scan mirror reflection versus scan angle (RVS)

  49. Aqua RSB Response Trending (Moon/SD)

  50. SD Degradation Trending SD door left open for 5 days due to a command drop SD door failure on July 2nd, 2003

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